The atmosphere of Mars is quite different from that of Earth. It is
composed primarily of carbon dioxide with small amounts of other gases.
The six most common components of the atmosphere are:
Carbon Dioxide (CO2): 95.32%
Nitrogen (N2): 2.7%
Argon (Ar): 1.6%
Oxygen (O2): 0.13%
Water (H2O): 0.03%
Neon (Ne): 0.00025 %
Martian air contains only about 1/1,000 as much water
as our air, but even this small amount can condense out, forming
clouds that ride high in the atmosphere or swirl around the slopes
of towering volcanoes. Local patches of early morning fog can form
in valleys. At the Viking Lander 2 site, a thin layer of water
frost covered the ground each winter.
There is evidence that in the past a denser martian
atmosphere may have allowed water to flow on the planet. Physical
features closely resembling shorelines, gorges, riverbeds and
islands suggest that great rivers once marked the planet.
Temperature and Pressure
The average recorded temperature on Mars is -63 C (-81 F)
with a maximum
temperature of 20 C (68 F) and a minimum of -140 C
(-220 F).
Barometric pressure varies at each landing site on a
semiannual basis. Carbon dioxide, the major constituent
of the atmosphere, freezes out to form an immense polar cap,
alternately at each pole. The carbon dioxide forms a great cover
of snow and then evaporates again with the coming of spring in
each hemisphere. When the southern cap was largest, the mean
daily pressure observed by Viking Lander 1 was as low as 6.8
millibars; at other times of the year it was as high as 9.0
millibars. The pressures at the Viking Lander 2 site were 7.3
and 10.8 millibars.
In comparison, the average pressure of the Earth is 1000 millibars.
Very good, technical article making point that NASA is not altering colors on Mars (beyond normal minimal adjustments to generate color images, of course).
From the article summary, I thought he meant "disassemble" as in reverse engineer and figure out how the things work, and I was thinking "cool, like open source nanotech."
But in reading the article, I found this is not what he's talking about. Instead he is talking about how to decommission various molecular nanotechnology (MNT) creations, and e.g. the difficulties that are created by shields and shells created around various small scale entities.
I think both of these sides to "disassembly" seem pretty damn important.
Well if you RTFPOTA (Read The First Page Of The Article), as I just did, you can see that it appears to be more of a profile of some arbitrary individuals than an actual survey of the underground or anything grand and sweeping like that.
#11: Rolling Papers
Despite innovations in pipes (such as the famous Protopipe) and bongs (such as the infamous Triple Chamber Mason jar bong), people continue to use rolling papers for their smoking enjoyment. Zig-Zag papers continue to be a popular choice, with others using everything from toilet paper to yellow pages. Small wonder: joints are fun, and that's not going to change for a long time.
BTW, in "researching" for this post, I found a site called "Smokedot" very similar to Slashdot. I wonder if there is a "Smokedot effect" too and what that would entail...
If you'll read the
article you just quoted, under "The Shuttle decision", the paragraphs starting with (emphasis all mine):
The final defining moment was when NASA, in desperation to see their only remaining project saved, went to the Air Force for its blessing.
NASA asked that the AF place all of their future launches on the shuttle instead of their current expendable launchers (like the Titan II), in return for which they would no longer have to continue spending money upgrading those designs -- the shuttle would provide more than enough capability.
The Air Force relucantly agreed, but only after demanding a large increase in capability to allow for launching their projected spy satellites (mirrors are heavy). These were quite large, weighing an estimated 40,000 lbs, and needed to be put into polar orbit, which requires more energy to get to than the more common low Earth orbit. And since the AF also wanted to be able to abort after a single orbit (as did NASA), and land at the launch site (unlike NASA), the spacecraft would also require the ability to manuver significantly to either side of its orbital track to adjust for the launching point rotating away from it while in polar orbit - in a 90 minute orbit Vandenberg would move over 1,000 miles, whereas in a "normal" equatorial orbit NASA needed the range would be less than 400. This large 'cross-range' capability meant the craft had to have a greater lift to drag ratio than originally planned. This required the addition of bigger, heavier wings.
[and the next several paragraphs...]
Anyway, my point stands, which is that the USAF was instrumental in shaping many of the decisions regarding the Shuttle. I don't entirely disagree with you, but you are very much underestimating this factor, and if you'll read the very article that you quoted, you'll start to catch some glimpses of this. There obviously was a lot more going on than a several paragraph summary can reveal, but you can see the significance of the changes and start to understand the desire to not have to continually redesign.
Very interesting post. Here's my take, very rough and unchecked.
Considering that we're talking about a potential 4-hour trip, I don't think we can look back 50,000 years for the distance. Right now, we're at a 10 light-minute distance between Earth and Mars, which works out to 1.8e11 m (or 180 million km), slightly 3x what you used. This calc is from: 1. d=rt; 2. d=ct; 3. d = (3e8 m/s) x (10 min) x (60 s/min).
Next, I'll calc how long to get to the halfway point, which is 9.0e10 m away. Using 1. d=(at^2)/2; 2. t=sqrt(2d/a); 3. t = sqrt(2 x (9.0e10 m) / (9.8 m/s^2)); We get t=1.355e5 s (135000 s), or 37.646 hours.
Doubling that for the full trip is 75.29 hours, or slightly over 3 days.
So I can say, we both got the same order of magnitude (several days), but for some reason the calculations are off. I figured the distance further but got a shorter trip... Can a third party verify one of these calculations please?
And as a quick check for validity of Newtonian calcs, assume constant speed travel in this time over this distance, and check what velocity would be roughly. Calc with 1. v=d/t; 2. v=(1.8e11 m) / (1.355e5 s); 3. v=1.3284e6 m/s. Compared to speed of light (c=3.0e8 m/s), this is, as you said, less than 1%. Newton rules here.
This (one way trip to Mars) has been discussed extensively in previous/. article.
I'm all for it, and there are many smart, sane, competent people who would make a good first team and die with dignity and honor. How sad it is that in modern western society we've elevated the individual human life to such an extent that we cannot see this...
Instead, we invested nearly everything into the Shuttle, which IMO has been a major diversion, as well as a money pit. The Shuttle is an amazing machine, but it still boils down to basically being a high-tech glider which can withstand re-entry (sometimes!).
The main reason NASA has been able to do anything over the last several decades is because of revenue/money. And a large part of that revenue has come from government agencies, especially the US Air Force. And the USAF required a launch vehicle with large payload capacity to bring up large satellites and the ability for humans to fix them. And once the USAF was behind NASA, the government was willing to put more money into the program because it seemed that much more important. And then the USAF put more in, because the government backed it... Etc. etc.
The shuttle has definitely cost a lot of money (and lives), and perhaps has lived longer than it should have, but it was an important step in our ascension to space. It is not entirely clear that any other path would have been faster or even possible, given the issue of funding, and the positive feedback loop resulting in getting the USAF and government behind the program.
The shuttle was a marvel for its time, and now somewhat antiquated in a large part due to the onward march of technology. This will be the history of every major human technological achievement for the forseeable future. It is easy to look back and see all the flaws. But it is not so easy to stop a multi-billion dollar project and start from scratch when you barely have the funds to continue operating on the current path.
That "bullshit" link you posted contains a really interesting story from a few months ago called "Dude, you're getting screwed" about how Dell screws over the customer wrt license agreements and has no ability or understanding of what they are even asking their customers to agree to. Take 5 minutes and read it.
I thought i read something somewhere about the bandwidth between Earth and the Spirit Rover being a ~100bps, so how can so many hi-res pics be sent back? Have i missed something here??
The data rate direct-to-Earth varies from about 12,000 bits per second to 3,500 bits per second (roughly a third as fast as a standard home modem). The data rate to the orbiters is a constant 128,000 bits per second (4 times faster than a home modem). An orbiter passes over the rover and is in the vicinity of the sky to communicate with the rovers for about eight minutes at a time, per sol. In that time, about 60 megabits of data (about 1/100 of a CD) can be transmitted to an orbiter. That same 60 megabits would take between 1.5 and 5 hours to transmit direct to Earth. The rovers can only transmit direct-to-Earth for at most three hours a day due to power and thermal limitations, even though Earth may be in view much longer.
The ~100bps figure may have been tossed around recently during the debugging of Spirit, while in its fault mode, but this is abnormally slow and not used during normal operations.
This is another good source of images, here organized by date. It doesn't have all the raw images, but it has all of the press release images and some extra ones on top of that. Generally images get posted here several hours before they are attached to press releases.
JPL MER2004 Image Archive
--
Can anyone explain to me why all the pictures look like they're taking through a fisheye lens? Why couldn't they have used a better camera?
The pancam has a field of view similar to a human being. It is 16.8 deg x 16.8 deg (0.293 x 0.293 radians).
The navcam has a wider field of view for use during driving, and to look at the immediate surroundings. It is 45 deg x 45 deg (0.79 x 0.79 radians).
You are seeing pictures from both of these cameras, because they are using both of these cameras. The navcam gives the appearance of a "fisheye" lens. The Pancam is in fact an extremely sophisticated and detailed digital camera, and it has two eyes to create stereoscopic (3D) images that make you feel like you're on Mars. Wait a few days and you'll see some more of these images. Click the link below to see some of the good ones from Spirit.
P.S. Anybody know how to make a degree symbol in a slashdot post?
The Pancams have two "eyes", as you noticed. Each has its own unique set of filters. Read more about the Pancam here.
The reason you are seeing mostly single shots now is because they are doing a lot of "real work" at the same time as streaming back pictures, and they need to conserve bandwidth and battery, as well as keeping the commands simple for now until they can run full diagnostics.
Another poster already mentioned it, but check out Hazy Hills Opportunity Stereo Images. It's nicely arranged for eye-crossing stereoscopic fun. There will be many more to come, but they're just getting started now.
FYI, that picture is a computer rendering of Mars, "created using Bryce and MOLA topographic data from NASA" (info here). Which is not to take anything away from it, because it's a stunning image, but let's not try to pass it off as a real photographic image.
Slashdot Mirror
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
More info on communications between Mars/Earth and the DSN (Deep Space Network):
- NASA's MER2004 Communications with Earth Overview
- DSN (Deep Space Network) Main Page
- Wikipedia entry on Deep Space Network
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Very good, technical article making point that NASA is not altering colors on Mars (beyond normal minimal adjustments to generate color images, of course).
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Take a look: More info and pictures of Fulgurites on Earth .
;-)
They look exactly like that thing on Mars.
BTW, Fulgurite reminds me of the Wizard's bad-ass "F" spell in Ultima 3 (Fulgar).
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
- Info (src: Athena)
- Tech Briefing (PDF 52 KB)
- Info (src: Planetary Society)
- Info (src: NASA)
- Info (src: Caves of Mars).
- Filter Specs
(showing approximate color swatches in browser).
--For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
For the lazy/short-attention-span/ADDHD, here's a quick link to:
Screen shot of MyDoom.A source code (160 KB GIF).
i just have my thai hooker click ACCEPT for me. she's under 18 and not even a citizen, so i'm pretty much in the clear.
Anyone know the IP in question?
It's 127.0.0.1. If you do manage to break in, see if you can find any interesting files, and go ahead and post them up here.
From the article summary, I thought he meant "disassemble" as in reverse engineer and figure out how the things work, and I was thinking "cool, like open source nanotech."
But in reading the article, I found this is not what he's talking about. Instead he is talking about how to decommission various molecular nanotechnology (MNT) creations, and e.g. the difficulties that are created by shields and shells created around various small scale entities.
I think both of these sides to "disassembly" seem pretty damn important.
I can write your name on a grain of rice, so don't you think I can boil the article down to a few lines?
my theory that the most dangerous people are people who are bored.
Yes, how else could the Slashdot effect be so devastating, if not for millions of bored nerds looking for something to click on?
Well if you RTFPOTA (Read The First Page Of The Article), as I just did, you can see that it appears to be more of a profile of some arbitrary individuals than an actual survey of the underground or anything grand and sweeping like that.
#11: Rolling Papers
Despite innovations in pipes (such as the famous Protopipe) and bongs (such as the infamous Triple Chamber Mason jar bong), people continue to use rolling papers for their smoking enjoyment. Zig-Zag papers continue to be a popular choice, with others using everything from toilet paper to yellow pages. Small wonder: joints are fun, and that's not going to change for a long time.
BTW, in "researching" for this post, I found a site called "Smokedot" very similar to Slashdot. I wonder if there is a "Smokedot effect" too and what that would entail...
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Very interesting post. Here's my take, very rough and unchecked.
Considering that we're talking about a potential 4-hour trip, I don't think we can look back 50,000 years for the distance. Right now, we're at a 10 light-minute distance between Earth and Mars, which works out to 1.8e11 m (or 180 million km), slightly 3x what you used. This calc is from: 1. d=rt; 2. d=ct; 3. d = (3e8 m/s) x (10 min) x (60 s/min).
Next, I'll calc how long to get to the halfway point, which is 9.0e10 m away. Using 1. d=(at^2)/2; 2. t=sqrt(2d/a); 3. t = sqrt(2 x (9.0e10 m) / (9.8 m/s^2)); We get t=1.355e5 s (135000 s), or 37.646 hours.
Doubling that for the full trip is 75.29 hours, or slightly over 3 days.
So I can say, we both got the same order of magnitude (several days), but for some reason the calculations are off. I figured the distance further but got a shorter trip... Can a third party verify one of these calculations please?
And as a quick check for validity of Newtonian calcs, assume constant speed travel in this time over this distance, and check what velocity would be roughly. Calc with 1. v=d/t; 2. v=(1.8e11 m) / (1.355e5 s); 3. v=1.3284e6 m/s. Compared to speed of light (c=3.0e8 m/s), this is, as you said, less than 1%. Newton rules here.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
This (one way trip to Mars) has been discussed extensively in previous /. article.
I'm all for it, and there are many smart, sane, competent people who would make a good first team and die with dignity and honor. How sad it is that in modern western society we've elevated the individual human life to such an extent that we cannot see this...
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
The shuttle has definitely cost a lot of money (and lives), and perhaps has lived longer than it should have, but it was an important step in our ascension to space. It is not entirely clear that any other path would have been faster or even possible, given the issue of funding, and the positive feedback loop resulting in getting the USAF and government behind the program.
The shuttle was a marvel for its time, and now somewhat antiquated in a large part due to the onward march of technology. This will be the history of every major human technological achievement for the forseeable future. It is easy to look back and see all the flaws. But it is not so easy to stop a multi-billion dollar project and start from scratch when you barely have the funds to continue operating on the current path.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
That "bullshit" link you posted contains a really interesting story from a few months ago called "Dude, you're getting screwed" about how Dell screws over the customer wrt license agreements and has no ability or understanding of what they are even asking their customers to agree to. Take 5 minutes and read it.
Perhaps you would be interested to read NASA's page: How Fast and How Much Data the Rovers Can Send Back, from which I quote:
The ~100bps figure may have been tossed around recently during the debugging of Spirit, while in its fault mode, but this is abnormally slow and not used during normal operations.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
This is another good source of images, here organized by date. It doesn't have all the raw images, but it has all of the press release images and some extra ones on top of that. Generally images get posted here several hours before they are attached to press releases.
JPL MER2004 Image Archive
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
I wonder what cpu is used on the rovers..
They use a radiation-hardened RAD6000 32-bit RISC chip made by BAE Systems. See their Press Release here. Bookmark the page in the link below.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
Can anyone explain to me why all the pictures look like they're taking through a fisheye lens? Why couldn't they have used a better camera?
The pancam has a field of view similar to a human being. It is 16.8 deg x 16.8 deg (0.293 x 0.293 radians).
The navcam has a wider field of view for use during driving, and to look at the immediate surroundings. It is 45 deg x 45 deg (0.79 x 0.79 radians).
You are seeing pictures from both of these cameras, because they are using both of these cameras. The navcam gives the appearance of a "fisheye" lens. The Pancam is in fact an extremely sophisticated and detailed digital camera, and it has two eyes to create stereoscopic (3D) images that make you feel like you're on Mars. Wait a few days and you'll see some more of these images. Click the link below to see some of the good ones from Spirit.
P.S. Anybody know how to make a degree symbol in a slashdot post?
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
The Pancams have two "eyes", as you noticed. Each has its own unique set of filters. Read more about the Pancam here.
The reason you are seeing mostly single shots now is because they are doing a lot of "real work" at the same time as streaming back pictures, and they need to conserve bandwidth and battery, as well as keeping the commands simple for now until they can run full diagnostics.
Another poster already mentioned it, but check out Hazy Hills Opportunity Stereo Images. It's nicely arranged for eye-crossing stereoscopic fun. There will be many more to come, but they're just getting started now.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
FYI, that picture is a computer rendering of Mars, "created using Bryce and MOLA topographic data from NASA" (info here). Which is not to take anything away from it, because it's a stunning image, but let's not try to pass it off as a real photographic image.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.